Whether it’s whining when they need to pee or those classic dog eyes when they want food, dogs have many tactics for communicating with their owners.
What we may not realize, however, is the intentionality behind some of these actions.
Researchers have explored this world of dog communication – which has evolved over thousands of years of domestication with humans – and are beginning to interpret their barks and attention-getting tricks.
The basis of dog barking
While dog barking may seem simple to the untrained ear, it is much more complex than one might think. Those who listen closely can learn to hear the difference.
A unique study published in Animal behavior studied types of dog barking back in 2004. In this work, a team put six different breeds in three different situations: one in which a stranger rings the doorbell, another in which the dog is isolated from its owner in a separate room, and one in which either two dogs or a person and a dog play together.
The results were fascinating. In situations of anxiety (scenario #1), dogs are more likely to bark less. In isolation and play situations, barks were more often higher pitched.
“[There are] several studies that show acoustic differences in cortices. Aggressive barking is lower and playful or fearful barking is higher,” says Leah Nettle, a dog and cat behaviorist who has not been involved in the 2004 study.
The frequency of a dog’s barking, Nettle says, can also vary depending on how the dog is feeling. While aggressive barking is likely to be single or less frequent, excited, high-pitched expressions will involve many barks.
Why is my dog barking so much?
Although a dog’s barking certainly gets on our nerves sometimes, we don’t know if the barking is annoying the dog itself. However, a dog’s barking can affect other dogs.
“Dogs will use body language to show they’re stressed, and they’ll use vocal communication to get their owner’s attention or push things away,” Nettle says.
In studies involving animal shelters, barking has been used as an indicator of dog welfare. “All the loud noise in the shelter is stressful for the dogs and can be physically terrifying for them,” Nettle says.
Stressed dogs
In addition to shelter settings, dogs often reflect the stress their owners feel. in 2019 a study published in Nature found that over long periods of time, a dog will synchronize its stress levels to match its owner. In other words, if the owner is upset, the dog is likely to respond to that emotion.
To measure stress levels in dogs and humans, researchers in the 2019 study looked at the concentration of cortisol in human and canine hair, or HCC. The results suggest a strong relationship between the concentration of HCC in humans and the concentration of HCC in their own dog.
Researchers have used certain models to analyze the effect of human HCC on canine HCC. Both dog breed and gender were included in the models to reduce potential confounding variables.
“Human HCC had a significant effect on canine HCC for both summer and winter samples. As HCC in humans increased, there was an increase in HCC in dogs,” the researchers wrote in learning.
While dog personality has little effect on HCC, human personality traits such as neuroticism, openness, and conscientiousness have a significant impact on dog HCC. In other words, a dog’s stress levels will change depending on whether its owner is more or less neurotic, open, and aware of its surroundings.
Read more: What to do if your pet struggles with anxiety
The evolution of canine communication
Believe it or not, dog barking didn’t just appear overnight. Unlike other pets, dogs are unique in that they have evolved alongside humans for several thousand years. The earliest signs of domestication were discovered 33,000 years ago, and fully domesticated dogs are common in the archaeological record beginning about 15,000 years ago.
“Dogs are unique in that they co-evolved with humans and we also domesticated them, so they have vocalizations that seem consistent with domestication,” Nettle says. “Dogs and wolves share a more recent ancestor, and dogs will bark more than wolves and in more contexts, so it appears that their communication is due to humans.”
Read more: How does your dog understand you?
The evolution of dogs: The transition from wolf to dog
The process of domesticating dogs must have been tedious.
It is unlikely that early human hunter-gatherers stole wolf pups and raised them themselves, according to 2021 survey in Current Biology. It is more likely that domestication occurred slowly, possibly by accident, as wolves acclimated to humans while scavenging animal carcasses.
This 2021 study found that wolf pups, no matter how well trained, still behave like wolves.
Domesticated dogs, meanwhile, show early emerging social skills that are likely the result of domestication altering their cognition. These social skills include communicating with their owners through barking and some non-verbal gestures.
A dog’s body language
Dogs rely on the use of gestures to communicate with their owners. Dogs can spontaneously use new and random gestures, such as using physical markers.
Additionally, dogs that are better at interpreting human gestures are more successful as service dogs. “This interspecies communication is unusual: dogs are more adept at using human gestures than maternally reared chimpanzees and other great apes,” the researchers wrote in learning.
The next time you hear your dog barking, think twice. There is a high probability that they will try to get your attention.
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